This invention relates to a spa, and to a so-called slide valve usable in controlling the admission of air into a circulated stream of liquid such as the water which is contained in a spa.
A conventional spa includes a tub portion which holds the water in the spa, and various electrically powered instrumentalities that are selectively controlled by a user to change the operating conditions of the spa. Among such instrumentalities may be a pump, which has its intake withdrawing water from the tub portion of the spa and its discharge connecting through a conduit to the tub of the spa with the pump being operated to produce water circulation. It is common practice to provide this conduit with a venturi-type of device which pulls air from the atmosphere into the stream of water being circulated, with such water and air then being ejected through a hydro jet into the tub portion of the spa.
To control the amount of air which is drawn into the circulated water, a valve is usually provided adjustable between loosed and open positions and which is operable upon adjustments made therein to shut off air flow or to permit various rates of air flow into the circulated water. Valves presently known have not been entirely satisfactory, such commonly being a rotary type of valve which does not clearly indicate its adjusted state and which is difficult to adjust to produce fine control of the flow rate of air introduced.
One object of this invention is to provide a spa which includes a slide valve for controlling air flow to the circulated water which may include an actuator movable along a path for adjusting the valve between a closed and various degrees of openness in position. The condition of the valve is readily observable, and accurate and fine control of the amount of air introduced is permitted.
Another object is to provide a spa with slide valve for controlling air flow where the valve has a construction such that for a given amount of movement in a closure element of the valve, the amount that the valve is opened increases as the closure element is moved progressively from a fully closed position.
A further object is to provide in such combination, a slide valve which includes a check valve which opens to permit air flow as drawn by a vacuum inwardly and through the valve but which closes to prevent a reverse flow of fluid through the valve.
In a specific and preferred embodiment of the invention, the slide valve includes a valve housing which has a cylindrical chamber extending along the interior thereof and a valve closure element reciprocally mounted within this chamber slidable along the length of the chamber. An elongate air admission slot in the housing extends along the length of this chamber which opens the chamber to the atmosphere. Movement of the closure element along this chamber varies the extent of the slot which connects with one end of the chamber, and a water and air mixer connected to this one end of the chamber. The closure element may be directly linked through a plunger connected therewith with an adjustment knob which the user utilizes in adjusting the position of the closure element. In the context of a spa, such adjustment knob may be presented on the exterior side of a control panel which is mounted in a convenient position adjacent the tub portion of the spa.
Further contemplated as an object of the invention is the provision of a novel slide valve for controlling air flow which is readily assembled from prefabricated parts and readily installed in an assembled state in an operative position, such as one controlling the admission of air into spa circulated water. The valve requires minimal maintenance, is economically produced, and is relatively easily repaired should such be necessary.